System of electrical distribution



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wwf nw R. D. DUNCAN. JR

SYSTEI OF ELECTRICAL DISTRIBUTION Filed June 7, 1930 @www minuta HAB mUDOW DUuQm +DDb Dec. 13, 1932.

MESES; negano Patented Dec. 13, 1932 Examaer PATENT OFFICE ROBERT D. DUNCAN, JR., OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WIRED RADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE SYSTEM OF ELECTRICAL DISTRIBUTION Application led June 7, 1930. Serial No. 459,785.

quency currents over electric light and power lines, it has been determined by actual operation that the light and power lines may have appreciable attenuation effects for the passage of high frequency currents. Such attenuation is brought about in part by the absorption of high frequency power by the lines, and in part by the absorption of hlgh frequency power by ordinary power equipment such as transformers, heating elements,

lamps, et cetera, which are connected across the lines. Certain sections of a light and power distribution system, such as the secondaries extending from distributlon transformers to the consumers local distribution circuits, generally offer greater attenuation than other sections of the distribution system.

One of the objects of my invention consists in providing means for substantially el1m1- nating excessive high frequency attenuation which electric light and power distribution systems oder to the transmission of high frequency currents.

Another object comprises providing in- I dependent wire lines between a light and power substation and a subscribers premises over which high frequency currents are transmitted.

A further object consists in providing a combined electric light and power high frequency distribution system and means for utilizing the subscribers house wiring system as a common means of local distribution of light and power and high frequency cur- 5o are independently distributed to a certain the said high frequency currents are im` pressed on the consumers local light and power distribution lines in a manner such that both power and light and high frequency signals are available at any of the consumers outlet sockets.

In the drawing accompanying and forming a part of this specification and in which like reference numerals designate corresponding parts throughout; I have schematically illustrated one embodiment of my invention.

Referring to the drawing, a source of light and power current 1 is situated in a substation 2. This source of light and power current may be either a power generator or transforming equipment. Lines 3 extend from the light and power source l and to step-down transformers 4 and 5. The transformers 5 and 4 supply proper voltages through secondary lines 6 and 7 for consumers dwellings 8 and 9, respectively. It is to be understood that the illustration of these transformers is merely re resentative of a secondary supply system. n actual practice, one transformer could serve several dwellings and could be situated some distance from the dwellings. Service switches 10 and 11 are interposed in the consumers local distribution circuits 6 and 7, respectively. A watthour meter 12 and fuse box 13 are provided in the local distribution circuit 6 and comprise normal service equipment of a consumers dwelling. The watthour meter 14 and fuse box 15 are also provided in the local distribution system 7 of the consumers dwelling 9.

In the substation 2 I provide an oscillator 16, a modulator 18 and an amplifier 17 all of which comprise a source of modulated high frequency signals. It is obvious that such source of high or raiiio frequency signals is situated in the substation 2 merely as a. mat- 100 ter of convenience, and could equally well be situated at any other point. Lines 19 extend from the modulator 18 and are adapted to carry high frequency signals. These lines 19 may be co-eXtcnsive with the power lines 13 or may be provided only in certain sections of the power distribution system where disturbing attenuation effects are particularly pronounced. In my invention I provide lines :2O connected to the lines 19 and capacitatively coupled to the local distribution lines 7 of the consumers dwelling 9 by means of condensers Q1 and Q2. These condensers 21 and 22 offer relatively low impedance to the passage of high frequency current-s and high impedance to the passage of low frequency and direct currents.

A signal blocker 23 comprising a choke coil 24 is in series with one of the lines 7 extending from the step down transformer 4. The choke coil Q4.- is essentially an inductance which blocks high frequency currents.

A similar arrangement is provided in the consumers dwelling 8 wherein lines Q5 eX- tend from the supply lines 19 to condensers 26 and 27, and signal blocker 28 comprising a choke coil 29 is interposed in the line 6 extending from the step down transformer 5.

The capacitative coupling between the high frequency lines and the consnmers distribution system may be connected to any point of the consumers local distribution system. It will be noted that the condensers 21 and 22 are connected into the lines 7 between the signal blocker 23 and the service switch 11 in dwelling 9, whereas the condensers 26 and 27 are connected to the lines 6 between the watthour meter 12 and the fuse box 13 in dwelling 8. These two examples illustrate two different methods of tying in radio frequency lines to the consumers distribution circuit which could be used to meet varying conditions of consumers wiring installation. The method of connection in the dwelling S has a particular advantage in that the field coils of the watthour meter 12 being in series with the choke coil 29 tend to increase the effectiveness of the choke coil in blocking high frequency currents.

For convenience of operation, it is highly desirable that wired radio receivers may be connected to any service outlet of t-he consumers dwelling so that the receiver can receive radio frequency signals as well as tube filament and plate operating voltages from one outlet. The receiver 23 is connected to the local distribution lines 6. Normal means are provided within the receiver 28 for receiving radio frequency signals in the line 6 by capacitative couplings and at the same time supplying necessary tube operating voltages by direct connections to the lines 6. A similar receiver 29 is provided in the consumers dwelling 9 and is connectedto the local distribution lines 7 thereof. It is obvious that any number of such receivers may be provided in the consumers dwelling for the reception of wired radio signals.

High frequency signals upon being impressed by the modulator 18 on the lines 19 are individually distributed to the consumers local distribution lines by means of the auxiliary lines 2O and 25 which extend from the high frequency lines 19. T he condensers 21 and QQ, and 26 and 27 serve as means for impressing the radio frequency currents on the local distribution lines of the consumers dwellings as hereinbefore described. Since these condensers offer high impedance to low frequency. and direct currents, the electric light and power currents carried on the secondary lines 6 and 7 and derived from the primary high tension line 3 will be prevented from feeding back into the high frequency lines 19. The blockers 23 and 28 in the secondary lines 7 and 6, respectively, will effectively prevent the feeding back of high frequency current into the electric light and power distribution system. The distribution of high frequency currents on the electric light and power lines is. therefore, confined to the local distribution lines of the consumers dwelling. It is, of course, obvious that the blockers 23 and 28 may be located somewhat removed from the consumers dwelling. as for example, in the immediatevicinity of the step down transformers 5 and 4 without departing from the scope of my invention. Also. it will be obvious that one blocker, such as blocker 28 might be utilized in a secondary distribution line serving several dwellings and. therefore, confine the high frequency distribution to secondary lines serving a group of consumers.

It will be apparent that the system herein described offers a satisfactory means of overcoming disturbing attenuation effects to be found in light and power distribution networks. and at the same time is of special advantage in that the normal operation of wired radio receiver from anv electric light and power service outlet of the consumers dwelling is permitted.

While I have shown but two consumers dwellings in association with an electric light adpower substation. it will. of course. be readily understood that mv electrical distribution system as hereinbefore described is readilv applicable to any number of consumers served by electric light and power lines from anv source. I do not. therefore. wish to be limited in my invent-ion except insofar as may be pointed out in the appended claims.

I claim:

1. In an electrical distribution system, a local distribution circuit confined within a consumers premises. a source of electric light and power current, wire lines adapted to deliver said light and power current to said local distribution circuit in said consumers premises, a source of modulated high frequency current, wire lines adapted to deliver said modulated high frequency current to said consumers premises, and means adapted to impress said high frequency currents on said local distribution circuit in said consumers premises only. v

2. In an electrical distribution system, a local distribution circuit within a consumers premises, a source of'commercial power including a substation, power lines for delivering commercial power from said substation to said local distribution circuit in said consumers premises, a source of modulated high frequency current, other wire lines for delivering said modulated high frequency to said consumers premises, coupling means between said wire lines and said consumers circuit for impressing said high frequency current thereon, and means connected in said local distribution circuit for restricting said high frequency current thereto.

3. In a system of electrical distribution, a power substation for supplying high voltage commercial power, a plurality of consumers circuits, power transformer equipment re mot-ely situated from said substation but connected therewith by power lines for supplying commercial power at reduced voltages to said consumers circuits, wire lines independent of said power lines and extending from said substation to said consumers circuits, means including an amplifier in said substation for supplying high frequency current to said wire lines, coupling means between said wire lines and said consumers circuits for supplying high frequency current thereto, and means connected in said consumers circuits for restricting said high frequency current thereto.

4. In a system of electrical distribution, a power substation for supplying highwoltage commercial power` a local distribution circuit confined within a consumers premises, power transformer equipment remotely situated from said substation but connected thereto by power line for supplying commercial power at reduced voltages to said consupplying high voltage commercial power, power transformer equipment remotely situated from said substation but connected therewith by power lines for supplying commercal power at reduced voltages to said local distribution circuit in said consumers premises, a source of modulated high frequency current, means independent of said power lines and said transformer equipment for delivering said modulated high frequency current to said consumers premises, and means adapted to impress said high frequency currents on said local distribution circuit in said consumers premises only.

6. In an electrical distribution system, a local distribution circuit confined within a consumers premises, a power substation for supplying high voltage commercial power, power transformer equipment remotely situated from said substation but connected therewith by power lines for supplying commercial power at reduced voltages to said local distribution circuit in said consumers premises, a source of modulated high frequency current, wire lines adapted to deliver said modulated high frequency current to said consumers premises, means coupling said wire lines to said local distribution circuit for impressing said high frequency current thereon, and means connected in said local distribution circuit for restricting said high frequency current thereto.

ROBERT D. DUNCAN, JR.

sumers circuits, means in said substation for amplifying modulated high frequency current, means independent of said power lines for transmitting modulated high frequency current from said substation to said consumers premises, means adapted to impress said high frequency current on said local distribution circuit in said consumers premises, and means for substantially preventing the passage of said high frequency currents from said local distribution circuit to said power lines.

5. In an electrical distribution system, a local distribution circuit confined within a consumers premises, a power substation for 

